London 2012: Bus workers to vote on action over bonus
London bus workers are to be balloted on whether to take industrial action over their demand for an Olympics bonus.
Union Unite has called for an extra £500 payment to "recognise and reward bus workers for the massive increase in workloads" during the Games.
It said a strike or other action could be considered if employers did not enter into "genuine talks".
Transport for London (TfL) said bus drivers were already paid overtime.
Various deals have already been agreed for London train and Tube workers, although a compromise has not yet been reached on the specific sum that London Underground workers will receive for work during the Games.
London buses are run by several operators, with First and Go Ahead among the largest.
London 2012 - One extraordinary year
Unite, which represents 24,000 bus workers, said every operator had refused to agree to meet with the union.
Unite regional secretary Peter Kavanagh called it a "massive error of judgement".
He said: "The London bus is an iconic symbol for London and bus workers will be on the front line dealing with the extra congestion and helping passengers find their way around."
Go Ahead did not comment.
Ken Davidson, head of bus operations for TfL, said it was "aware and disappointed" by Unite's decision.
He added: "London bus drivers are employed by private bus companies and their pay and conditions are set by those companies.
"If bus drivers are required to work additional hours they are paid overtime accordingly."